Add Hashicorp Vault golang library
What does this MR do?
Adds Hashicorp Vault API library.
Note for the reviewer: It's only a vendoring update. No other code than updating go.{mod,sum}
files and vendor/
directory (will be required by an upcoming MR).
Why was this MR needed?
Step one for #26565 (closed)
What's the best way to test this MR?
What are the relevant issue numbers?
Edited by Tomasz Maczukin